Should the human resources department lead attempts to improve productivity via performance management and appraisal?
Expecting the human resources department to take the lead in making performance management work almost always fails. It's not because HR people are stupid. It's because HR lacks the line authority to make it work. That, and many HR people are intent on solving THEIR problems, rather than the problems of managers and employees. Nice folks, but not placed well to lead this.
A short answer, but that's it in a nutshell. That's NOT to say the human resource department has no role to play. It has a HUGE role to play, but not in terms of leading the charge to improve management.